RNDC.CONF(5) BIND9 RNDC.CONF(5)
NAME
rndc.conf - rndc configuration file
SYNOPSIS
rndc.conf
DESCRIPTION
rndc.conf is the configuration file for rndc, the BIND 9 name server control utility. This file has a similar structure and syntax to
named.conf. Statements are enclosed in braces and terminated with a semi-colon. Clauses in the statements are also semi-colon terminated.
The usual comment styles are supported:
C style: /* */
C++ style: // to end of line
Unix style: # to end of line
rndc.conf is much simpler than named.conf. The file uses three statements: an options statement, a server statement and a key statement.
The options statement contains five clauses. The default-server clause is followed by the name or address of a name server. This host will
be used when no name server is given as an argument to rndc. The default-key clause is followed by the name of a key which is identified by
a key statement. If no keyid is provided on the rndc command line, and no key clause is found in a matching server statement, this default
key will be used to authenticate the server's commands and responses. The default-port clause is followed by the port to connect to on the
remote name server. If no port option is provided on the rndc command line, and no port clause is found in a matching server statement,
this default port will be used to connect. The default-source-address and default-source-address-v6 clauses which can be used to set the
IPv4 and IPv6 source addresses respectively.
After the server keyword, the server statement includes a string which is the hostname or address for a name server. The statement has
three possible clauses: key, port and addresses. The key name must match the name of a key statement in the file. The port number specifies
the port to connect to. If an addresses clause is supplied these addresses will be used instead of the server name. Each address can take
an optional port. If an source-address or source-address-v6 of supplied then these will be used to specify the IPv4 and IPv6 source
addresses respectively.
The key statement begins with an identifying string, the name of the key. The statement has two clauses. algorithm identifies the
encryption algorithm for rndc to use; currently only HMAC-MD5 is supported. This is followed by a secret clause which contains the base-64
encoding of the algorithm's encryption key. The base-64 string is enclosed in double quotes.
There are two common ways to generate the base-64 string for the secret. The BIND 9 program rndc-confgen can be used to generate a random
key, or the mmencode program, also known as mimencode, can be used to generate a base-64 string from known input. mmencode does not ship
with BIND 9 but is available on many systems. See the EXAMPLE section for sample command lines for each.
EXAMPLE
options {
default-server localhost;
default-key samplekey;
};
server localhost {
key samplekey;
};
server testserver {
key testkey;
addresses { localhost port 5353; };
};
key samplekey {
algorithm hmac-md5;
secret "6FMfj43Osz4lyb24OIe2iGEz9lf1llJO+lz";
};
key testkey {
algorithm hmac-md5;
secret "R3HI8P6BKw9ZwXwN3VZKuQ==";
};
In the above example, rndc will by default use the server at localhost (127.0.0.1) and the key called samplekey. Commands to the localhost
server will use the samplekey key, which must also be defined in the server's configuration file with the same name and secret. The key
statement indicates that samplekey uses the HMAC-MD5 algorithm and its secret clause contains the base-64 encoding of the HMAC-MD5 secret
enclosed in double quotes.
If rndc -s testserver is used then rndc will connect to server on localhost port 5353 using the key testkey.
To generate a random secret with rndc-confgen:
rndc-confgen
A complete rndc.conf file, including the randomly generated key, will be written to the standard output. Commented-out key and controls
statements for named.conf are also printed.
To generate a base-64 secret with mmencode:
echo "known plaintext for a secret" | mmencode
NAME SERVER CONFIGURATION
The name server must be configured to accept rndc connections and to recognize the key specified in the rndc.conf file, using the controls
statement in named.conf. See the sections on the controls statement in the BIND 9 Administrator Reference Manual for details.
SEE ALSO
rndc(8), rndc-confgen(8), mmencode(1), BIND 9 Administrator Reference Manual.
AUTHOR
Internet Systems Consortium
COPYRIGHT
Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
Copyright (C) 2000, 2001 Internet Software Consortium.
BIND9 June 30, 2000 RNDC.CONF(5)